Question

a compound contain 81.8g carbon and 18.2g of hydrogen its molecular mass is 132.0g whats its emperical and molecular formula​

Answer 1

Answer:

Carbon : 81.8

Hydrogen : 18.2

moles of carbon : 81.8/12 = 6.81 mol

moles of hydrogen : 18.2/1 = 18 .2 mol

mole ratio - C:H = 1 : 2.67

simplest ratio - 3 : 8

Emperical Formula = C3H8

Formula wt = 3(12) +8(1) =36+8 = 44g

mol wt = 132g

we know : mol wt = n × formula wt

: 132 = 44n

: n =3

Mol. Formula = C9H24

Answer 2

Given:

A compound contains 81.8g carbon and 18.2g of hydrogen

Its molecular mass is 132.0g

To Find:

Its empirical and molecular formula

Solution:

It is given that a compound contains 81.8g of carbon so, the moles of carbon is 12 so, 18.8/12 = 6.81 mol

and, that same compound contains 18.2g of hydrogen moles of hydrogen = 18.2/1 = 2 mol

The mole ratio = C: H    

[carbon is denoted by C and hydrogen is denoted by H].

                         = 1: 2.67

The simplest ratio is 3:8

Empirical formula = C3H8

Formula wt = 3(12) +8(1) = 36+8= 44g

      mol wt  = 132g

       mol wt = n × formula wt

         132 = 44n

           n = 3

Molecular formula is C9H24